Thursday, October 04, 2007

Brain radiator

In severe epileptic fits, over-excited brain cells fire at such a rate they can raise the brain's temperature in that area. This causes more nerves to fire in a feedback mechanism that makes the fit even worse. One way of preventing such escalating fits is to cool the area of the brain that is susceptible.

So Takashi Saito and colleagues at Yamaguchi University in Japan have developed a heat pipe that is surgically implanted into the affected region of the brain and then connected to a heat sink on the outside of the skull. This device carries heat away from the affected area, keeping it cool and reducing the chances of severe epileptic fits in future.

But seriously, a heat pipe works by vaporizing a liquid at the bottom, then liquidizing it at the top. Thus, heat pipes only work one way. A small heat pipe will conduct the same amount of heat into the skull as a couple strands of hair.

This probably applies to more epileptics than it may seem - it is common knowledge (although maybe not scientific proven) that epileptic seizures can be prevented for some patients, if they don't use too hot water when washing their hair. A relative of mine has reduced her seizures, and look at this article, I suddenly realize that this coincides with her hair cut changing from long hair to short...

A heatpipe is a freegin piece of thermally conductive metal... AKA, it transfers heat very well.

Yes, but...

The efficiency of transferring heat down the heat pipe is much lower than the efficiency going upward. It's a difference of pure conduction along the metal tube (which is relatively thin) vs the evaporative cooling effect of the heat pipe. (The primary mode of operation)

Also, heat pipes have a set temperature that the evaporative cooling effect starts working at, determined by the pressure inside the pipe and characteristics of the cooling fluid, so you can in essence "set" the temperature that it starts cooling at to prevent the brain from getting too cold.

My worry wouldn't so much be a "brain freeze" as much as a fluid spill INTO the brain from either a damaged or corroded heat pipe. One can only assume they would take some precautions against this however.

Heatpipes depend more on wicking and capilary action than gravity. Many heatpipes don't even have liquid (in the sense most people think of liquids) just somewhat aerosol droplets that vaporate easily. Heatpipes are mostly vacuum and wire mesh on the inside.

You still have to worry about a stick of metal hanging out your skull poking through your meninges...the image of the fan on the heatpipe is all the more disconcerting.